you do not mention a key fob. Do you have a working key fob?...When I say working, can you lock or unlock ANY of the doors with a key fob?.
you can program just about any diamond BMW key (or one found on ebay) to work with your car as long as you have at least one key that works in the ignition. Look online for the procedure.
I would program a new or used key fob (even a used one on ebay which does not work in your ignition) to lock/unlock your doors and see what happens.
If a key ONLY locks but does not unlock your door(s), like the central lock button, I would begin to think it is your GM module
you can program just about any diamond BMW key (or one found on ebay) to work with your car as long as you have at least one key that works in the ignition. Look online for the procedure.
I would program a new or used key fob (even a used one on ebay which does not work in your ignition) to lock/unlock your doors and see what happens.
If a key ONLY locks but does not unlock your door(s), like the central lock button, I would begin to think it is your GM module